Loom thread cutter



May 12, 1959 J. A. CUGlNl 2,886,070

LOOM THREAD CUTTER Filed Dec. 10, 1956 iii INVENTOR. Joan: H. Cuc-nm A TTORNE Y United States Patent 'ce LOOM THREAD CUTTER John A. Cugini, Hopedale, Mass., assignor to Draper Corporation, Hopedale, Mass, a corporation of Maine Application December 10, 1956, Serial No. 627,372

6 Claims. (Cl. 139-266) This invention pertains to improvements in thread cutters for looms, for example, temple thread cutters, of the type which function intermittently.

It is a general object of the invention to cut the period of time during which a temple thread cutter shall operate to a small fraction of the total weaving time of the loom.

A more specific object is that of devising a scissors type thread cutter which shall be controlled so that its blades, although actuated at each movement of the loom lay, will make shearing contact only at a few picks in the cycle of weaving from bobbin to bobbin during which the filling is to be cut.

It is further object to effect shearing engagement between these blades by pneumatically functioning means.

Other objects of the invention will become apparent from the following more detailed disclosure.

In automatic looms a thread cutter carried by a temple is provided to cut the outgoing and the ingoing ends at the selvage. Of course, the cutting function is required once after each replenishing cycle, but while that might involve operating the cutter for a few seconds, in practice,

most loom-s function by actuating the cutter once for each beat of the lay. This means that the mechanism operates hundreds of times for the few picks during which it is needed with the attendant wear, noise and, of course, expense for repairs and replacements.

Attempts have been made to devise cutters which shall function at desired times only and also some have been tried which function one pick out of every ten, for example. However, none of these has been practical enough to have gone into anything like commercial usage.

According to the instant invention, a thread cutter of the scissors type such, for example, as that of US. Patent 2,718,242, is so actuated by the loom lay that one of its blades is actuated at each beat up motion. However, by means to be described in detail, the blades are permitted to make shearing engagement only at such part of the cycle as a thread is to be cut. More specifically, a preferred form involves the use of pneumatic means to engage a blade or blades which are otherwise held out of shearing contact in any convenient manner, e.g., by a spring. This pneumatic control is timed, preferably by being tied in with a transfer mechanism at which compressed air may be available and utilized for other pur poses. However, a supply of air may be taken from any convenient source and need not be tied in with other air actuated devices, but, however, a timing control of some nature is contemplated.

The invention will be disclosed in detail by a description of one specific embodiment thereof as illustrated in the accompanying figures of drawing, wherein:

Fig. 1 is a plan view of a temple thread cutter with the invention applied thereto.

Fig. 2 is an elevation of the mechanism of Fig. 1.

Fig. 3 is an end view of the cutter and temple.

Fig. 4 is a section taken at line 4-4, Fig. 1.

Now referring to Figs. 1, 2 and 3, the cutter is mounted upon a temple having the usual bar 10, head 11 and a roll A 2,886,070 Patented May 12, 1959 enclosing pad and cap 12. The bar is mounted in the usual slide (not shown) and is adapted to reciprocate therein when the lip 13 is contacted by a part of the lay at beat-up.

The cutter is mounted upon the head 11 and comprises a lower or fixed scissor blade 14 which is held in place by a screw 15, and a cooperating movable blade 16. The latter is attached to an arm 17 of a lever pivoted at 18 and which also has an angularly disposed arm 19 with a toe 20 which is positioned to be contacted by a pad or other extension on the lay.

This lever is not only pivoted, but is also biased in a direction to open the cutter blades since the pivot is constituted as a torsion bushing. A stud 21 is held in the head 11 and has fixed thereon a rubber bushing 22 upon which the hub of the lever is clamped as shown. The parts are maintained axially and also angularly as in Fig. 3, but the rubber may be stressed as the blade 16 is moved in a shearing action with blade 14. The action of such a cutter is described in detail in the patent, above noted.

According to the invention, the movable blade preferably, but at least one of them, is so mounted as to be displaced to and from the other blade so that when it is desired to cut, they act as a shear, but at other times, will not make contact at all. For that purpose, blade 16 is shaped with a more or less horizontal web 23 through which pases a shoulder screw 24 threaded into arm 17 near its end. The blade may swing freely for a limited extent on this screw, but is otherwise caused to act as a part of the arm to move in its shearing action.

The blade further has an extension or arm 25 by which it is controlled. Here the governing influence is in the form of a spring which normally draws the extension or arm and the blade outwardly away from shearing contact, and air pressure means to press it against the spring to that position. Specifically, this means comprises a cylinder 26 and a piston 27 and rod 28. The cylinder has a source of compressed air connected to it by a tube 29 and connection 30. Piston 27 is rendered tight by a conventional O-ring and a spring 33 continuously urges the parts to the left, Fig. 4. Thus, rod 28 attached in any convenient manner to arm 25, for example, by snap rings 31, 32, pulls the arm and also blade 16 about pivot 24 to a position in which it makes no shearing contact with the opposed blade 14. The blade will, of course, be moved as the lever is oscillated at pivot 18 at each beat of the loom lay.

When it becomes desirable to cut a thread or threads, air pressure is admitted to the cylinder and the piston, being driven forwardly against spring 33, pushes arm 25 to swing blade 16 into shearing relationship with blade 14. The cutter immediately becomes active to cut any threads which may enter between its blades. The diiference between the air pressure at the piston and the spring force is so calculated that the correct pressure at the blades for a clean yet easy shearing action shall be obtained.

In practical installations the cutter if a temple thread cutter is to be operated to sever the filling ends at the fabric selvage shortly after replenishment and accordingly the air pressure is applied to the piston at that time only, for about 10-20 picks. At all other times the blades are out of contact. Control is by a timer not necessary to be described here but which may be for this express purpose only or it may also control other functions, some at least of which involve pneumatic devices supplied from the same source.

Thus it can be seen that while the movable cutter parts are actuated at each pick of weaving, the blades do not engage at their shearing edges except for a few picks when thread is to be cut and the life of the blades and their cutaesemo 3 ting edges are preserved over a much greater period of time.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invent'ion and the scope of the claims.

I claim:

1. In combination in a loom having a reciprocating lay, a lay actuated thread cutter having cooperating shearing blades, a pneumatically operated means for lmaintaining said blades out of shearing engagement except at such time as the cutter is to be actuated to sever a thread.

2. In combination in a loom having a reciprocating lay, a lay actuated thread cutter having cooperating shearing blades, means to effect shearing engagement between said blades and other means for maintaining said blades out of shearing engagement except at such times as the cutter is to be actuated to sever a thread.

3. In combination in a loom having a reciprocating lay, alay actuated thread cutter having cooperating shearing blades, means to maintain said blades out of shearing engagement during normal operation and other means eitective when a thread is to be cut, for establishing shearing contact between said blades.

4. In combination in a loom having a reciprocating lay, a lay actuated thread cutter having cooperating shearing blades, resilient means normally effective for maintaining said blades out of shearing engagement and pneumatically actuated means effective When a thread is to be cut, for establishing shearing contact between said blades.

5. Mechanism as defined in claim 4 wherein said resilient means comprises a spring and said pneumatically actuated means comprises a cylinder, means to admit air under pressure to said cylinder and a piston and rod movable against said spring, and means to convey movement of the piston and rod to one of said shearing blades.

6. In combination in a loom having a reciprocating lay,

a lay actuated thread cutter having a fixed shear blade,

a pivoted lever and a movable shear blade, means for attaching said movable shear blade to one end of said lever comprising a pivot means upon which it is free to swing to and from shearing engagement with said fixed blade, an arm for swinging said movable blade about its pivot, resilient means for maintaining the arm and its blade in a position in which there is no shearing contact between blades and pneumatic means for swinging the arm and blade to a shearing position.

References Cited in the file of this patent UNITED STATES PATENTS 2,718,242 Nichols Sept. 20., 1-955 

